<?php
/**
 * Ruth Library
 * $Id: Conditions.php 2 2008-01-17 02:59:56Z baron314159@yahoo.com $
 *
 * LICENSE
 *
 * Copyright (c) 2007, Chris Utz
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the Impact Lab nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY CHRIS UTZ ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL CHRIS UTZ BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @category   Ruth
 * @package    Ruth_Channel
 * @author     Chris Utz <chris@chrisutz.com>
 * @copyright  2007 Chris Utz <chris@chrisutz.com>
 * @license    http://www.opensource.org/licenses/bsd-license.php    New BSD License
 * @version    $Revision: 2 $
 */

/**
 * @see Ruth_Channel_Validate_Omni
 */
require_once 'Ruth/Channel/Validate/Omni.php';

/**
 * @see Ruth_Validate_Exception
 */
require_once 'Ruth/Validate/Exception.php';

/**
 * Allows more complicated validation rules to be composed in the rare
 * cases it is necessary.
 *
 * @category   Ruth
 * @package    Ruth_Channel
 * @subpackage Ruth_Channel_Validate
 * @author     Chris Utz <chris@chrisutz.com>
 * @copyright  2007 Chris Utz <chris@chrisutz.com>
 * @license    http://www.opensource.org/licenses/bsd-license.php    New BSD License
 * @version    $Revision: 2 $
 */
class Ruth_Channel_Validate_Conditions extends Ruth_Channel_Validate_Omni
{
    /**
     * Condition types
     */
    const AND_CONDITION = 'and';
    const OR_CONDITION  = 'or';
    const AND_PUSH      = 'andPush';
    const OR_PUSH       = 'orPush';
    const POP           = 'pop';

    /**
     * @var array
     */
    protected $_conditions;

    /**
     * @param string $value Not used in this class.
     * @return boolean
     */
    public function isValid($value)
    {
        list($notUsed, $result) = $this->_meetsConditions(0);
        return $result;
    }

    /**
     * 
     */
    public function condition($fieldName, $param, array $options=array(), $type=self::AND_CONDITION)
    {
        if ($param instanceof Ruth_Validate_Abstract) {
            $validator = $param;
        } else {
            $validator = Ruth_Validate::instantiate($param, $options);
        }

        $this->_conditions[] = array($type, $fieldName, $validator);
        return $this;
    }

    /**
     * 
     */
    public function andCondition($fieldName, $param, array $options=array())
    {
        return $this->condition($fieldName, $param, $options, self::AND_CONDITION);
    }

    /**
     * 
     */
    public function orCondition($fieldName, $param, array $options=array())
    {
        return $this->condition($fieldName, $param, $options, self::OR_CONDITION);
    }

    /**
     * 
     */
    public function push($type=self::AND_PUSH)
    {
        $this->_conditions[] = $type;
        return $this;
    }

    /**
     * 
     */
    public function andPush()
    {
        return $this->push(self::AND_PUSH);
    }

    /**
     * 
     */
    public function orPush()
    {
        return $this->push(self::OR_PUSH);
    }

    /**
     * 
     */
    public function pop()
    {
        $this->_conditions[] = self::POP;
        return $this;
    }

    /**
     * 
     */
    protected function _meetsConditions($index)
    {
        $result = true;

        for ($i=$index; $i < count($this->_conditions); $i++) {
            $condition = $this->_conditions[$i];

            if ($condition == self::AND_PUSH) {
                list($i, $pushResult) = $this->_meetsConditions($i+1);
                $result = ($result and $pushResult);
            } else if ($condition == self::OR_PUSH) {
                list($i, $pushResult) = $this->_meetsConditions($i+1);
                $result = ($result or $pushResult);
            } else if ($condition == self::POP) {
                return array($i, $result);
            } else {
                if (!is_array($condition)) {
                    throw new Ruth_Validate_Exception("invalid condition type {$condition}");
                }

                list($type, $fieldName, $validator) = $condition;

                if ($validator instanceof Ruth_Channel_Validate_Omni) {
                    $validator->setFields($this->getFields());
                }

                $otherValue = $this->getFieldValue($fieldName);

                if (is_null($otherValue)) {
                    throw new Ruth_Validate_Exception("{$fieldName} not in field list");
                }

                $isValid = $validator->isValid($otherValue);

                switch ($type) {
                    case self::AND_CONDITION:
                        $result = ($result and $isValid);
                        break;
                    case self::OR_CONDITION:
                        $result = ($result or $isValid);
                        break;
                    default:
                        throw new Ruth_Validate_Exception("invalid condition type {$type}");
                }
            }
        }

        return array($i, $result);
    }
}
 
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